[PATCH][tree-optimization]Optimize combination of comparisons to dec+compare

[PATCH][tree-optimization]Optimize combination of comparisons to dec+compare

[Eugene Rozenfeld]

[-- Attachment #1: Type: text/plain, Size: 2163 bytes --]

Ping.

-----Original Message-----
From: Eugene Rozenfeld 
Sent: Tuesday, December 22, 2020 3:01 PM
To: Richard Biener <richard.guenther@gmail.com>; gcc-patches@gcc.gnu.org
Subject: RE: Optimize combination of comparisons to dec+compare

Re-sending my question and re-attaching the patch.

Richard, can you please clarify your feedback?

Thanks,

Eugene

-----Original Message-----
From: Gcc-patches <gcc-patches-bounces@gcc.gnu.org> On Behalf Of Eugene Rozenfeld via Gcc-patches
Sent: Tuesday, December 15, 2020 2:06 PM
To: Richard Biener <richard.guenther@gmail.com>
Cc: gcc-patches@gcc.gnu.org
Subject: [EXTERNAL] Re: Optimize combination of comparisons to dec+compare

Richard,

> Do we already handle x < y || x <= CST to x <= y - CST?

That is an invalid transformation: e.g., consider x=3, y=4, CST=2.
Can you please clarify?

Thanks,

Eugene

-----Original Message-----
From: Richard Biener <richard.guenther@gmail.com> 
Sent: Thursday, December 10, 2020 12:21 AM
To: Eugene Rozenfeld <Eugene.Rozenfeld@microsoft.com>
Cc: gcc-patches@gcc.gnu.org
Subject: Re: Optimize combination of comparisons to dec+compare

On Thu, Dec 10, 2020 at 1:52 AM Eugene Rozenfeld via Gcc-patches <gcc-patches@gcc.gnu.org> wrote:
>
> This patch adds a pattern for optimizing x < y || x == XXX_MIN to x <= 
> y-1 if y is an integer with TYPE_OVERFLOW_WRAPS.

Do we already handle x < y || x <= CST to x <= y - CST?
That is, the XXX_MIN case is just a special-case of generic anti-range testing?  For anti-range testing with signed types we pun to unsigned when possible.

> This fixes pr96674.
>
> Tested on x86_64-pc-linux-gnu.
>
> For this function
>
> bool f(unsigned a, unsigned b)
> {
>     return (b == 0) | (a < b);
> }
>
> the code without the patch is
>
> test   esi,esi
> sete   al
> cmp    esi,edi
> seta   dl
> or     eax,edx
> ret
>
> the code with the patch is
>
> sub    esi,0x1
> cmp    esi,edi
> setae  al
> ret
>
> Eugene
>
> gcc/
> PR tree-optimization/96674
> * match.pd: New pattern x < y || x == XXX_MIN --> x <= y - 1
>
> gcc/testsuite
> * gcc.dg/pr96674.c: New test.
>

[-- Attachment #2: 0001-Optimize-combination-of-comparisons-to-dec-compare.patch --]
[-- Type: application/octet-stream, Size: 2504 bytes --]

From 39215c58f5f640920d81cbe43503342c8b518cd9 Mon Sep 17 00:00:00 2001
From: Eugene Rozenfeld <erozen@microsoft.com>
Date: Wed, 9 Dec 2020 16:44:25 -0800
Subject: [PATCH] Optimize combination of comparisons to dec+compare

This patch adds a pattern for optimizing
x < y || x == XXX_MIN to x <= y-1
if y is an integer with TYPE_OVERFLOW_WRAPS.

This fixes pr96674.

Tested on x86_64-pc-linux-gnu.

For this function

bool f(unsigned a, unsigned b)
{
    return (b == 0) | (a < b);
}

the code without the patch is

test   esi,esi
sete   al
cmp    esi,edi
seta   dl
or     eax,edx
ret

the code with the patch is

sub    esi,0x1
cmp    esi,edi
setae  al
ret

gcc/
PR tree-optimization/96674
* match.pd: New pattern x < y || x == XXX_MIN --> x <= y - 1

gcc/testsuite
* gcc.dg/pr96674.c: New test.
---
 gcc/match.pd                   |  7 +++++++
 gcc/testsuite/gcc.dg/pr96674.c | 28 ++++++++++++++++++++++++++++
 2 files changed, 35 insertions(+)
 create mode 100644 gcc/testsuite/gcc.dg/pr96674.c

diff --git a/gcc/match.pd b/gcc/match.pd
index 68201ff2e07..c29af540152 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -2084,6 +2084,13 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
     (if (eqne == NE_EXPR)
      { constant_boolean_node (true, type); }))))
 
+/* x < y || x == XXX_MIN --> x <= y - 1 */
+(simplify
+ (bit_ior (eq @1 min_value) (lt @0 @1))
+  (if (INTEGRAL_TYPE_P (TREE_TYPE (@1))
+       && TYPE_OVERFLOW_WRAPS (TREE_TYPE (@1)))
+  (le @0 (minus @1 { build_int_cst (TREE_TYPE (@1), 1); }))))
+
 /* Convert (X == CST1) && (X OP2 CST2) to a known value
    based on CST1 OP2 CST2.  Similarly for (X != CST1).  */
 
diff --git a/gcc/testsuite/gcc.dg/pr96674.c b/gcc/testsuite/gcc.dg/pr96674.c
new file mode 100644
index 00000000000..c7f20bffabb
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr96674.c
@@ -0,0 +1,28 @@
+/* { dg-do run } */
+/* { dg-options "-O -fdump-tree-optimized -fwrapv" } */
+
+#include <limits.h>
+#include <stdbool.h>
+
+bool __attribute__ ((noinline)) test1 (unsigned a, unsigned b)
+{
+    return (b == 0) | (a < b);
+}
+
+bool __attribute__ ((noinline)) test2 (int a, int b)
+{
+    return (b == INT_MIN) | (a < b);
+}
+
+int main()
+{
+    if (!test1 (1, 0) || !test1 (1, 2) || test1 (2, 1) ||
+        !test2 (1, INT_MIN) || !test2 (1, 2) || test2 (2, 1)) {
+        __builtin_abort();	
+    }
+
+    return 0;
+}
+
+/* { dg-final { scan-tree-dump-times "\\+ 4294967295;" 1 "optimized" } } */
+/* { dg-final { scan-tree-dump-times "\\+ -1;" 1 "optimized" } } */
-- 
2.17.1

Re: [PATCH][tree-optimization]Optimize combination of comparisons to dec+compare

[Richard Biener]

On Mon, Jan 4, 2021 at 9:50 PM Eugene Rozenfeld
<Eugene.Rozenfeld@microsoft.com> wrote:
>
> Ping.
>
> -----Original Message-----
> From: Eugene Rozenfeld
> Sent: Tuesday, December 22, 2020 3:01 PM
> To: Richard Biener <richard.guenther@gmail.com>; gcc-patches@gcc.gnu.org
> Subject: RE: Optimize combination of comparisons to dec+compare
>
> Re-sending my question and re-attaching the patch.
>
> Richard, can you please clarify your feedback?

Hmm, OK.

The patch is OK.

Thanks,
Richard.


> Thanks,
>
> Eugene
>
> -----Original Message-----
> From: Gcc-patches <gcc-patches-bounces@gcc.gnu.org> On Behalf Of Eugene Rozenfeld via Gcc-patches
> Sent: Tuesday, December 15, 2020 2:06 PM
> To: Richard Biener <richard.guenther@gmail.com>
> Cc: gcc-patches@gcc.gnu.org
> Subject: [EXTERNAL] Re: Optimize combination of comparisons to dec+compare
>
> Richard,
>
> > Do we already handle x < y || x <= CST to x <= y - CST?
>
> That is an invalid transformation: e.g., consider x=3, y=4, CST=2.
> Can you please clarify?
>
> Thanks,
>
> Eugene
>
> -----Original Message-----
> From: Richard Biener <richard.guenther@gmail.com>
> Sent: Thursday, December 10, 2020 12:21 AM
> To: Eugene Rozenfeld <Eugene.Rozenfeld@microsoft.com>
> Cc: gcc-patches@gcc.gnu.org
> Subject: Re: Optimize combination of comparisons to dec+compare
>
> On Thu, Dec 10, 2020 at 1:52 AM Eugene Rozenfeld via Gcc-patches <gcc-patches@gcc.gnu.org> wrote:
> >
> > This patch adds a pattern for optimizing x < y || x == XXX_MIN to x <=
> > y-1 if y is an integer with TYPE_OVERFLOW_WRAPS.
>
> Do we already handle x < y || x <= CST to x <= y - CST?
> That is, the XXX_MIN case is just a special-case of generic anti-range testing?  For anti-range testing with signed types we pun to unsigned when possible.
>
> > This fixes pr96674.
> >
> > Tested on x86_64-pc-linux-gnu.
> >
> > For this function
> >
> > bool f(unsigned a, unsigned b)
> > {
> >     return (b == 0) | (a < b);
> > }
> >
> > the code without the patch is
> >
> > test   esi,esi
> > sete   al
> > cmp    esi,edi
> > seta   dl
> > or     eax,edx
> > ret
> >
> > the code with the patch is
> >
> > sub    esi,0x1
> > cmp    esi,edi
> > setae  al
> > ret
> >
> > Eugene
> >
> > gcc/
> > PR tree-optimization/96674
> > * match.pd: New pattern x < y || x == XXX_MIN --> x <= y - 1
> >
> > gcc/testsuite
> > * gcc.dg/pr96674.c: New test.
> >

RE: [EXTERNAL] Re: [PATCH][tree-optimization]Optimize combination of comparisons to dec+compare

[Eugene Rozenfeld]

[-- Attachment #1: Type: text/plain, Size: 3371 bytes --]

I got more feedback for the patch from Gabriel Ravier and Jakub Jelinek in https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96674 and re-worked it accordingly.

The changes from the previous patch are:
1. Switched the tests to use __attribute__((noipa)) instead of __attribute__((noinline)) .
2. Fixed a type in the pattern comment.
3. Added :c for top-level bit_ior expression.
4. Added :s for the subexpressions.
5. Added a pattern for the negated expression:
    x >= y && y != XXX_MIN --> x > y - 1
    and the corresponding tests.

The new patch is attached.

Eugene

-----Original Message-----
From: Richard Biener <richard.guenther@gmail.com> 
Sent: Tuesday, January 5, 2021 4:21 AM
To: Eugene Rozenfeld <Eugene.Rozenfeld@microsoft.com>
Cc: gcc-patches@gcc.gnu.org
Subject: [EXTERNAL] Re: [PATCH][tree-optimization]Optimize combination of comparisons to dec+compare

On Mon, Jan 4, 2021 at 9:50 PM Eugene Rozenfeld <Eugene.Rozenfeld@microsoft.com> wrote:
>
> Ping.
>
> -----Original Message-----
> From: Eugene Rozenfeld
> Sent: Tuesday, December 22, 2020 3:01 PM
> To: Richard Biener <richard.guenther@gmail.com>; 
> gcc-patches@gcc.gnu.org
> Subject: RE: Optimize combination of comparisons to dec+compare
>
> Re-sending my question and re-attaching the patch.
>
> Richard, can you please clarify your feedback?

Hmm, OK.

The patch is OK.

Thanks,
Richard.


> Thanks,
>
> Eugene
>
> -----Original Message-----
> From: Gcc-patches <gcc-patches-bounces@gcc.gnu.org> On Behalf Of 
> Eugene Rozenfeld via Gcc-patches
> Sent: Tuesday, December 15, 2020 2:06 PM
> To: Richard Biener <richard.guenther@gmail.com>
> Cc: gcc-patches@gcc.gnu.org
> Subject: [EXTERNAL] Re: Optimize combination of comparisons to 
> dec+compare
>
> Richard,
>
> > Do we already handle x < y || x <= CST to x <= y - CST?
>
> That is an invalid transformation: e.g., consider x=3, y=4, CST=2.
> Can you please clarify?
>
> Thanks,
>
> Eugene
>
> -----Original Message-----
> From: Richard Biener <richard.guenther@gmail.com>
> Sent: Thursday, December 10, 2020 12:21 AM
> To: Eugene Rozenfeld <Eugene.Rozenfeld@microsoft.com>
> Cc: gcc-patches@gcc.gnu.org
> Subject: Re: Optimize combination of comparisons to dec+compare
>
> On Thu, Dec 10, 2020 at 1:52 AM Eugene Rozenfeld via Gcc-patches <gcc-patches@gcc.gnu.org> wrote:
> >
> > This patch adds a pattern for optimizing x < y || x == XXX_MIN to x 
> > <=
> > y-1 if y is an integer with TYPE_OVERFLOW_WRAPS.
>
> Do we already handle x < y || x <= CST to x <= y - CST?
> That is, the XXX_MIN case is just a special-case of generic anti-range testing?  For anti-range testing with signed types we pun to unsigned when possible.
>
> > This fixes pr96674.
> >
> > Tested on x86_64-pc-linux-gnu.
> >
> > For this function
> >
> > bool f(unsigned a, unsigned b)
> > {
> >     return (b == 0) | (a < b);
> > }
> >
> > the code without the patch is
> >
> > test   esi,esi
> > sete   al
> > cmp    esi,edi
> > seta   dl
> > or     eax,edx
> > ret
> >
> > the code with the patch is
> >
> > sub    esi,0x1
> > cmp    esi,edi
> > setae  al
> > ret
> >
> > Eugene
> >
> > gcc/
> > PR tree-optimization/96674
> > * match.pd: New pattern x < y || x == XXX_MIN --> x <= y - 1
> >
> > gcc/testsuite
> > * gcc.dg/pr96674.c: New test.
> >

[-- Attachment #2: 0002-Optimize-combination-of-comparisons-to-dec-compare.patch --]
[-- Type: application/octet-stream, Size: 3172 bytes --]

From 689f3becbc6f6d7265c7b6fc4367910c82997fd4 Mon Sep 17 00:00:00 2001
From: Eugene Rozenfeld <erozen@microsoft.com>
Date: Wed, 9 Dec 2020 16:44:25 -0800
Subject: [PATCH] Optimize combination of comparisons to dec+compare

This patch adds patterns for optimizing
x < y || y == XXX_MIN to x <= y-1
x >= y && y != XXX_MIN to x > y-1
if y is an integer with TYPE_OVERFLOW_WRAPS.

This fixes pr96674.

Tested on x86_64-pc-linux-gnu.

For this function

bool f(unsigned a, unsigned b)
{
    return (b == 0) | (a < b);
}

the code without the patch is

test   esi,esi
sete   al
cmp    esi,edi
seta   dl
or     eax,edx
ret

the code with the patch is

sub    esi,0x1
cmp    esi,edi
setae  al
ret

gcc/
PR tree-optimization/96674
* match.pd: New patterns: x < y || y == XXX_MIN --> x <= y - 1
x >= y && y != XXX_MIN --> x > y - 1

gcc/testsuite
* gcc.dg/pr96674.c: New tests.
---
 gcc/match.pd                   | 14 ++++++++++++
 gcc/testsuite/gcc.dg/pr96674.c | 40 ++++++++++++++++++++++++++++++++++
 2 files changed, 54 insertions(+)
 create mode 100644 gcc/testsuite/gcc.dg/pr96674.c

diff --git a/gcc/match.pd b/gcc/match.pd
index 6f7b41fe0ff..cc1a876f0f2 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -2147,6 +2147,20 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
     (if (eqne == NE_EXPR)
      { constant_boolean_node (true, type); }))))
 
+/* y == XXX_MIN || x < y --> x <= y - 1 */
+(simplify
+ (bit_ior:c (eq:s @1 min_value) (lt:s @0 @1))
+  (if (INTEGRAL_TYPE_P (TREE_TYPE (@1))
+       && TYPE_OVERFLOW_WRAPS (TREE_TYPE (@1)))
+  (le @0 (minus @1 { build_int_cst (TREE_TYPE (@1), 1); }))))
+
+/* y != XXX_MIN && x >= y --> x > y - 1 */
+(simplify
+ (bit_and:c (ne:s @1 min_value) (ge:s @0 @1))
+  (if (INTEGRAL_TYPE_P (TREE_TYPE (@1))
+       && TYPE_OVERFLOW_WRAPS (TREE_TYPE (@1)))
+  (gt @0 (minus @1 { build_int_cst (TREE_TYPE (@1), 1); }))))
+
 /* Convert (X == CST1) && (X OP2 CST2) to a known value
    based on CST1 OP2 CST2.  Similarly for (X != CST1).  */
 
diff --git a/gcc/testsuite/gcc.dg/pr96674.c b/gcc/testsuite/gcc.dg/pr96674.c
new file mode 100644
index 00000000000..194ce2e6352
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr96674.c
@@ -0,0 +1,40 @@
+/* { dg-do run } */
+/* { dg-options "-O -fdump-tree-optimized -fwrapv" } */
+
+#include <limits.h>
+#include <stdbool.h>
+
+bool __attribute__ ((noipa)) test1 (unsigned a, unsigned b)
+{
+    return (b == 0) | (a < b);
+}
+
+bool __attribute__ ((noipa)) test2 (int a, int b)
+{
+    return (b == INT_MIN) | (a < b);
+}
+
+bool __attribute__ ((noipa)) test3 (unsigned a, unsigned b)
+{
+    return (b != 0) & (a >= b);
+}
+
+bool __attribute__ ((noipa)) test4 (int a, int b)
+{
+    return (b != INT_MIN) & (a >= b);
+}
+
+int main()
+{
+    if (!test1 (1, 0) || !test1 (1, 2) || test1 (2, 1) ||
+        !test2 (1, INT_MIN) || !test2 (1, 2) || test2 (2, 1) ||
+        test3 (1, 0) || test3 (1, 2) || !test3 (2, 1) ||
+        test4 (1, INT_MIN) || test4 (1, 2) || !test4 (2, 1)) {
+        __builtin_abort();	
+    }    	
+
+    return 0;
+}
+
+/* { dg-final { scan-tree-dump-times "\\+ 4294967295;" 2 "optimized" } } */
+/* { dg-final { scan-tree-dump-times "\\+ -1;" 2 "optimized" } } */
-- 
2.17.1

Re: [EXTERNAL] Re: [PATCH][tree-optimization]Optimize combination of comparisons to dec+compare

[Richard Biener]

On Thu, Jan 14, 2021 at 10:04 PM Eugene Rozenfeld
<Eugene.Rozenfeld@microsoft.com> wrote:
>
> I got more feedback for the patch from Gabriel Ravier and Jakub Jelinek in https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96674 and re-worked it accordingly.
>
> The changes from the previous patch are:
> 1. Switched the tests to use __attribute__((noipa)) instead of __attribute__((noinline)) .
> 2. Fixed a type in the pattern comment.
> 3. Added :c for top-level bit_ior expression.
> 4. Added :s for the subexpressions.
> 5. Added a pattern for the negated expression:
>     x >= y && y != XXX_MIN --> x > y - 1
>     and the corresponding tests.
>
> The new patch is attached.

OK.

Thanks,
Richard.

> Eugene
>
> -----Original Message-----
> From: Richard Biener <richard.guenther@gmail.com>
> Sent: Tuesday, January 5, 2021 4:21 AM
> To: Eugene Rozenfeld <Eugene.Rozenfeld@microsoft.com>
> Cc: gcc-patches@gcc.gnu.org
> Subject: [EXTERNAL] Re: [PATCH][tree-optimization]Optimize combination of comparisons to dec+compare
>
> On Mon, Jan 4, 2021 at 9:50 PM Eugene Rozenfeld <Eugene.Rozenfeld@microsoft.com> wrote:
> >
> > Ping.
> >
> > -----Original Message-----
> > From: Eugene Rozenfeld
> > Sent: Tuesday, December 22, 2020 3:01 PM
> > To: Richard Biener <richard.guenther@gmail.com>;
> > gcc-patches@gcc.gnu.org
> > Subject: RE: Optimize combination of comparisons to dec+compare
> >
> > Re-sending my question and re-attaching the patch.
> >
> > Richard, can you please clarify your feedback?
>
> Hmm, OK.
>
> The patch is OK.
>
> Thanks,
> Richard.
>
>
> > Thanks,
> >
> > Eugene
> >
> > -----Original Message-----
> > From: Gcc-patches <gcc-patches-bounces@gcc.gnu.org> On Behalf Of
> > Eugene Rozenfeld via Gcc-patches
> > Sent: Tuesday, December 15, 2020 2:06 PM
> > To: Richard Biener <richard.guenther@gmail.com>
> > Cc: gcc-patches@gcc.gnu.org
> > Subject: [EXTERNAL] Re: Optimize combination of comparisons to
> > dec+compare
> >
> > Richard,
> >
> > > Do we already handle x < y || x <= CST to x <= y - CST?
> >
> > That is an invalid transformation: e.g., consider x=3, y=4, CST=2.
> > Can you please clarify?
> >
> > Thanks,
> >
> > Eugene
> >
> > -----Original Message-----
> > From: Richard Biener <richard.guenther@gmail.com>
> > Sent: Thursday, December 10, 2020 12:21 AM
> > To: Eugene Rozenfeld <Eugene.Rozenfeld@microsoft.com>
> > Cc: gcc-patches@gcc.gnu.org
> > Subject: Re: Optimize combination of comparisons to dec+compare
> >
> > On Thu, Dec 10, 2020 at 1:52 AM Eugene Rozenfeld via Gcc-patches <gcc-patches@gcc.gnu.org> wrote:
> > >
> > > This patch adds a pattern for optimizing x < y || x == XXX_MIN to x
> > > <=
> > > y-1 if y is an integer with TYPE_OVERFLOW_WRAPS.
> >
> > Do we already handle x < y || x <= CST to x <= y - CST?
> > That is, the XXX_MIN case is just a special-case of generic anti-range testing?  For anti-range testing with signed types we pun to unsigned when possible.
> >
> > > This fixes pr96674.
> > >
> > > Tested on x86_64-pc-linux-gnu.
> > >
> > > For this function
> > >
> > > bool f(unsigned a, unsigned b)
> > > {
> > >     return (b == 0) | (a < b);
> > > }
> > >
> > > the code without the patch is
> > >
> > > test   esi,esi
> > > sete   al
> > > cmp    esi,edi
> > > seta   dl
> > > or     eax,edx
> > > ret
> > >
> > > the code with the patch is
> > >
> > > sub    esi,0x1
> > > cmp    esi,edi
> > > setae  al
> > > ret
> > >
> > > Eugene
> > >
> > > gcc/
> > > PR tree-optimization/96674
> > > * match.pd: New pattern x < y || x == XXX_MIN --> x <= y - 1
> > >
> > > gcc/testsuite
> > > * gcc.dg/pr96674.c: New test.
> > >

RE: [EXTERNAL] Re: [PATCH][tree-optimization]Optimize combination of comparisons to dec+compare

[Eugene Rozenfeld]

Richard,

Can you please commit this patch for me? I don't have write access yet, I'm still working on getting copyright assignment/disclaimer signed by my employer.

Thanks,

Eugene

-----Original Message-----
From: Richard Biener <richard.guenther@gmail.com> 
Sent: Friday, January 15, 2021 3:55 AM
To: Eugene Rozenfeld <Eugene.Rozenfeld@microsoft.com>
Cc: gabravier@gmail.com; jakub@gcc.gnu.org; gcc-patches@gcc.gnu.org
Subject: Re: [EXTERNAL] Re: [PATCH][tree-optimization]Optimize combination of comparisons to dec+compare

On Thu, Jan 14, 2021 at 10:04 PM Eugene Rozenfeld <Eugene.Rozenfeld@microsoft.com> wrote:
>
> I got more feedback for the patch from Gabriel Ravier and Jakub Jelinek in https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgcc.gnu.org%2Fbugzilla%2Fshow_bug.cgi%3Fid%3D96674&amp;data=04%7C01%7CEugene.Rozenfeld%40microsoft.com%7Cf4b1e41de6b4469fd3bb08d8b94c5a20%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C637463084866262315%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&amp;sdata=%2Fc77uS%2BNlNGmXwOmK729BByEW0VDiq1HEe8BA7DpI30%3D&amp;reserved=0 and re-worked it accordingly.
>
> The changes from the previous patch are:
> 1. Switched the tests to use __attribute__((noipa)) instead of __attribute__((noinline)) .
> 2. Fixed a type in the pattern comment.
> 3. Added :c for top-level bit_ior expression.
> 4. Added :s for the subexpressions.
> 5. Added a pattern for the negated expression:
>     x >= y && y != XXX_MIN --> x > y - 1
>     and the corresponding tests.
>
> The new patch is attached.

OK.

Thanks,
Richard.

> Eugene
>
> -----Original Message-----
> From: Richard Biener <richard.guenther@gmail.com>
> Sent: Tuesday, January 5, 2021 4:21 AM
> To: Eugene Rozenfeld <Eugene.Rozenfeld@microsoft.com>
> Cc: gcc-patches@gcc.gnu.org
> Subject: [EXTERNAL] Re: [PATCH][tree-optimization]Optimize combination 
> of comparisons to dec+compare
>
> On Mon, Jan 4, 2021 at 9:50 PM Eugene Rozenfeld <Eugene.Rozenfeld@microsoft.com> wrote:
> >
> > Ping.
> >
> > -----Original Message-----
> > From: Eugene Rozenfeld
> > Sent: Tuesday, December 22, 2020 3:01 PM
> > To: Richard Biener <richard.guenther@gmail.com>; 
> > gcc-patches@gcc.gnu.org
> > Subject: RE: Optimize combination of comparisons to dec+compare
> >
> > Re-sending my question and re-attaching the patch.
> >
> > Richard, can you please clarify your feedback?
>
> Hmm, OK.
>
> The patch is OK.
>
> Thanks,
> Richard.
>
>
> > Thanks,
> >
> > Eugene
> >
> > -----Original Message-----
> > From: Gcc-patches <gcc-patches-bounces@gcc.gnu.org> On Behalf Of 
> > Eugene Rozenfeld via Gcc-patches
> > Sent: Tuesday, December 15, 2020 2:06 PM
> > To: Richard Biener <richard.guenther@gmail.com>
> > Cc: gcc-patches@gcc.gnu.org
> > Subject: [EXTERNAL] Re: Optimize combination of comparisons to
> > dec+compare
> >
> > Richard,
> >
> > > Do we already handle x < y || x <= CST to x <= y - CST?
> >
> > That is an invalid transformation: e.g., consider x=3, y=4, CST=2.
> > Can you please clarify?
> >
> > Thanks,
> >
> > Eugene
> >
> > -----Original Message-----
> > From: Richard Biener <richard.guenther@gmail.com>
> > Sent: Thursday, December 10, 2020 12:21 AM
> > To: Eugene Rozenfeld <Eugene.Rozenfeld@microsoft.com>
> > Cc: gcc-patches@gcc.gnu.org
> > Subject: Re: Optimize combination of comparisons to dec+compare
> >
> > On Thu, Dec 10, 2020 at 1:52 AM Eugene Rozenfeld via Gcc-patches <gcc-patches@gcc.gnu.org> wrote:
> > >
> > > This patch adds a pattern for optimizing x < y || x == XXX_MIN to 
> > > x <=
> > > y-1 if y is an integer with TYPE_OVERFLOW_WRAPS.
> >
> > Do we already handle x < y || x <= CST to x <= y - CST?
> > That is, the XXX_MIN case is just a special-case of generic anti-range testing?  For anti-range testing with signed types we pun to unsigned when possible.
> >
> > > This fixes pr96674.
> > >
> > > Tested on x86_64-pc-linux-gnu.
> > >
> > > For this function
> > >
> > > bool f(unsigned a, unsigned b)
> > > {
> > >     return (b == 0) | (a < b);
> > > }
> > >
> > > the code without the patch is
> > >
> > > test   esi,esi
> > > sete   al
> > > cmp    esi,edi
> > > seta   dl
> > > or     eax,edx
> > > ret
> > >
> > > the code with the patch is
> > >
> > > sub    esi,0x1
> > > cmp    esi,edi
> > > setae  al
> > > ret
> > >
> > > Eugene
> > >
> > > gcc/
> > > PR tree-optimization/96674
> > > * match.pd: New pattern x < y || x == XXX_MIN --> x <= y - 1
> > >
> > > gcc/testsuite
> > > * gcc.dg/pr96674.c: New test.
> > >

Re: [EXTERNAL] Re: [PATCH][tree-optimization]Optimize combination of comparisons to dec+compare

[Richard Biener]

On Wed, Jan 20, 2021 at 2:32 AM Eugene Rozenfeld
<Eugene.Rozenfeld@microsoft.com> wrote:
>
> Richard,
>
> Can you please commit this patch for me? I don't have write access yet, I'm still working on getting copyright assignment/disclaimer signed by my employer.

Done after re-bootstrapping/testing on x86-64-linux.

Richard.

> Thanks,
>
> Eugene
>
> -----Original Message-----
> From: Richard Biener <richard.guenther@gmail.com>
> Sent: Friday, January 15, 2021 3:55 AM
> To: Eugene Rozenfeld <Eugene.Rozenfeld@microsoft.com>
> Cc: gabravier@gmail.com; jakub@gcc.gnu.org; gcc-patches@gcc.gnu.org
> Subject: Re: [EXTERNAL] Re: [PATCH][tree-optimization]Optimize combination of comparisons to dec+compare
>
> On Thu, Jan 14, 2021 at 10:04 PM Eugene Rozenfeld <Eugene.Rozenfeld@microsoft.com> wrote:
> >
> > I got more feedback for the patch from Gabriel Ravier and Jakub Jelinek in https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgcc.gnu.org%2Fbugzilla%2Fshow_bug.cgi%3Fid%3D96674&amp;data=04%7C01%7CEugene.Rozenfeld%40microsoft.com%7Cf4b1e41de6b4469fd3bb08d8b94c5a20%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C637463084866262315%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&amp;sdata=%2Fc77uS%2BNlNGmXwOmK729BByEW0VDiq1HEe8BA7DpI30%3D&amp;reserved=0 and re-worked it accordingly.
> >
> > The changes from the previous patch are:
> > 1. Switched the tests to use __attribute__((noipa)) instead of __attribute__((noinline)) .
> > 2. Fixed a type in the pattern comment.
> > 3. Added :c for top-level bit_ior expression.
> > 4. Added :s for the subexpressions.
> > 5. Added a pattern for the negated expression:
> >     x >= y && y != XXX_MIN --> x > y - 1
> >     and the corresponding tests.
> >
> > The new patch is attached.
>
> OK.
>
> Thanks,
> Richard.
>
> > Eugene
> >
> > -----Original Message-----
> > From: Richard Biener <richard.guenther@gmail.com>
> > Sent: Tuesday, January 5, 2021 4:21 AM
> > To: Eugene Rozenfeld <Eugene.Rozenfeld@microsoft.com>
> > Cc: gcc-patches@gcc.gnu.org
> > Subject: [EXTERNAL] Re: [PATCH][tree-optimization]Optimize combination
> > of comparisons to dec+compare
> >
> > On Mon, Jan 4, 2021 at 9:50 PM Eugene Rozenfeld <Eugene.Rozenfeld@microsoft.com> wrote:
> > >
> > > Ping.
> > >
> > > -----Original Message-----
> > > From: Eugene Rozenfeld
> > > Sent: Tuesday, December 22, 2020 3:01 PM
> > > To: Richard Biener <richard.guenther@gmail.com>;
> > > gcc-patches@gcc.gnu.org
> > > Subject: RE: Optimize combination of comparisons to dec+compare
> > >
> > > Re-sending my question and re-attaching the patch.
> > >
> > > Richard, can you please clarify your feedback?
> >
> > Hmm, OK.
> >
> > The patch is OK.
> >
> > Thanks,
> > Richard.
> >
> >
> > > Thanks,
> > >
> > > Eugene
> > >
> > > -----Original Message-----
> > > From: Gcc-patches <gcc-patches-bounces@gcc.gnu.org> On Behalf Of
> > > Eugene Rozenfeld via Gcc-patches
> > > Sent: Tuesday, December 15, 2020 2:06 PM
> > > To: Richard Biener <richard.guenther@gmail.com>
> > > Cc: gcc-patches@gcc.gnu.org
> > > Subject: [EXTERNAL] Re: Optimize combination of comparisons to
> > > dec+compare
> > >
> > > Richard,
> > >
> > > > Do we already handle x < y || x <= CST to x <= y - CST?
> > >
> > > That is an invalid transformation: e.g., consider x=3, y=4, CST=2.
> > > Can you please clarify?
> > >
> > > Thanks,
> > >
> > > Eugene
> > >
> > > -----Original Message-----
> > > From: Richard Biener <richard.guenther@gmail.com>
> > > Sent: Thursday, December 10, 2020 12:21 AM
> > > To: Eugene Rozenfeld <Eugene.Rozenfeld@microsoft.com>
> > > Cc: gcc-patches@gcc.gnu.org
> > > Subject: Re: Optimize combination of comparisons to dec+compare
> > >
> > > On Thu, Dec 10, 2020 at 1:52 AM Eugene Rozenfeld via Gcc-patches <gcc-patches@gcc.gnu.org> wrote:
> > > >
> > > > This patch adds a pattern for optimizing x < y || x == XXX_MIN to
> > > > x <=
> > > > y-1 if y is an integer with TYPE_OVERFLOW_WRAPS.
> > >
> > > Do we already handle x < y || x <= CST to x <= y - CST?
> > > That is, the XXX_MIN case is just a special-case of generic anti-range testing?  For anti-range testing with signed types we pun to unsigned when possible.
> > >
> > > > This fixes pr96674.
> > > >
> > > > Tested on x86_64-pc-linux-gnu.
> > > >
> > > > For this function
> > > >
> > > > bool f(unsigned a, unsigned b)
> > > > {
> > > >     return (b == 0) | (a < b);
> > > > }
> > > >
> > > > the code without the patch is
> > > >
> > > > test   esi,esi
> > > > sete   al
> > > > cmp    esi,edi
> > > > seta   dl
> > > > or     eax,edx
> > > > ret
> > > >
> > > > the code with the patch is
> > > >
> > > > sub    esi,0x1
> > > > cmp    esi,edi
> > > > setae  al
> > > > ret
> > > >
> > > > Eugene
> > > >
> > > > gcc/
> > > > PR tree-optimization/96674
> > > > * match.pd: New pattern x < y || x == XXX_MIN --> x <= y - 1
> > > >
> > > > gcc/testsuite
> > > > * gcc.dg/pr96674.c: New test.
> > > >